Furnace



Meh H w29m G. P. JACKSON FURNACE Filed March 29, 1922 2 Sheets-Sheet lmama H lll INVENTQR. @eerm/ BM ATTO EYS.

2 Sheets-Sheet 2 FURNACE G. P. JACKSON Filed March 29,1922

Feb. 12', 1929.

NVENTJR.

M .al 363 Patented F eb. 12., 1929.

UNITED STTES PATENT OFFICE.

GEORGE PERCY JACKSON, OF NEW YORK, Y., ASSIGNOR TO COMBUSTION ENGINEER-ING' CORPORATION, 0F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

FURNACE.

Application led March 29, 1922. Serial No. 547,679.

The present invention has special reference to means for assisting'combustion in a furnace, and reducing liability of clinlrers and otherinjurious deposits forming on the wall of the fire-box of a furnace.

A n lObject of the invention is to provide a novel and improved means ofthis character which is particularly adapted for use in a pulverizedfuel furnace.

Another object of the invention is to provide a novel and improvedcombustion chamber for a furnace.

The several features of the invention whereby the above mentioned andother objects of the invention may be attained will be clearlyunderstood from the following description and accompanying drawings, inwhich Fig. l is a longitudinal vertical sectional view, partly inelevation, of a portion of a pulverized fuel furnace embodying thefeatures of the invention in their preferred form;

Fig. 2 is a transverse vertical sectional view taken on the line 2-2 ofFig. 1;

Fig. 3 is a vertical sectional view, on an enlarged scale and'vpartlybroken away, of a portion of a side wall of the tire-box of the'furnace;

Fig. 4 is a front view of the portion of the side wall illustrated inFig. 3; and

Fig. 5 is a sectional plan view taken the line 5-5 of Fig. 3.

rlhe pulverized fuel furnace illustrated in the drawings is providedwith a steam boiler 2, and a fire-box 4 having side walls 6, front wall7, rear or bridge wall 8, atop wall 10, and a bottom wall 11. Apulverized fuel nozzle 12, suitably connected with a source of fuelsupply is mounted in the top wall and is so arranged as to direct thepulverized fuel downwardly into the lire-box. In this type of furnacethe combustion of the fuel takes place while the fuel is in suspensionand the furnace dnaft tends to direct the Vsuspended mass of burningfuel and the gases upwardly to the boiler as indicated by arrows in Fig.l of the drawings.

As illustrated the inner sides of the four vertical walls of thefire-box are each provided with recesses 14 extending the length thereofand arranged one above the other :and spaced apart, with the recesses ofthe four walls opening one into the other to form a series of threerecesses completely encompassing the interior of the lire-box. Therecesses 14 are provided with horizontal upper and lowerwalls 16 and therecesses in the front and side walls of the fire-box are provided withan inner vertical wall 18. The recesses in the bridge wall 8 of thefire-box lead from an air chamber 2O formed in the bridge wall, which isconnected at its lower end with a suitable source of air supply througha pipe 22. The portions of the walls of the fire-box between therecesses 14, the portions of the walls immediately below the lowerrecesses 14 and the portions of the walls above the upper recesses 14are pro vided vwith downwardly and inwardly inclined surfaces 24. Aseries of blocks 26 of refractory material are :arranged end to end inthe recesses 14 so as to form three rows of blocks completelyencompassing the interior of the fire-box. The blocks 26 in the frontand side walls of the fire-box are spaced from the vertical walls of therecesses 14 so as to provide air passages 28 leading from the airchamber- 20, and the blocks in the bridge wall 8 extend through therecesses,

so that the three rows of blocks are completely surrounded by air spacesin communication with a source of air supply. The blocks 26 project adistance beyond the upper edges of the inclined surface 24 0f thefirewalls, and the inner surfaces of the blocks are inclined similarlyto the inclined surfaces 24 and form continuations thereof.

Each block 26 is provided with two downwardly directed air ducts 30 thatare in communication with the air passages 28 and the air chamber 20,through two channels 32 in the top of the block. The walls 34 of the airducts 30 are inclined the same as the inclined surfaces 24 of thefire-wall, and are so arranged as to form continuations of thesesur-faces. The other wall 36 of the air ducts 32 are at a less angle tothe vertical than the walls 34 and these walls are so spaced as toprovide a relatively wide and shallow passage between them that tapersdownwardly. With this construction it will be apparent that upon theadmission of air to the air chamber 2O the air duets 30 will direct thinfilms of air downwardly over the inclined surfaces 24 beneath the rowsof blocks, respectively, and that this air after. passing below the massof burning fuel will be drawn upwardly by the furnace draft and thusassist combustion and tend to maintain the heavier particles of burningfuel in suspension that would otherwise drop to the bottom of thefurnace only partially burned.

VThe downwardly directed air for combustion in connection withthedownwardly moving portion of the fuel and Haine-stream, isadvantageous as there is less violent eddying of the descending streamthan would be'the case were the air admittedrthrough the front wall orside wall in a direction transversev that ofthe descending fuel.Furthermore, where there are a plurality of burners-thereis a tendencyofv the air when admitted horizontally through the front wall, to shortcircuit some of the fuel directly to the tubes, particularly in theupper part of the combustion chamber before the individual streams yofentering fuel have had' opportunity to' unite in one general stream. ThedownwardV admission of the air obviates this; In addition, the downwardadmission of the air causes such air to travel farther alongwith thefuel stream bordering iton `the convex side before com- 'mingling takesplace. This tends tov insure the body' of air for the heavier particlesto ravitate into and there find the oxygen forcombustion..

It niayfalso be noted-thatthe downward admissionvr of air adjacent Vtheascending por! 'tion'of thefuel is advantageous for the reaf son that atsuchfl'placefmore.violent eddying of "theffu'el' and flame stream "isrequired -to secure 'the' "intimatey admixture ynecessary *to completecombustion'. In the ascending portionl ofthe 'fuel and *flamey streamthere are vlar'ge'bodies of expanded gases'and v4since the Volume is sogreat there is :need for more or less violent eddyin'g to'fge't the'proper admixture. In contra-distinction lthe entering fiel yhas someAofV theairV required4V for comi bustio/nffwith' itand,-therefo`re,a'i-lessfmcas urel ff eddying' 'is required *Itwill'also be apparentth'atthe cooling eifect'fofjthe air 'films on 'theinclined surfacesf'Qff-f of the' fire-*wall will tend to pre I venttheVformation of clinlzers thereon and tofprevent these surfacesfrom wearing away orf'spallingi '."These films of air directed over the vinclinedyvsurfaces also will 'te-nd =to preventv vcinders' `or dust lodgingvon-these sur# fa"ces"and" toi'dire'ct" it inwardly toward I the center':of `"thelirelbo'x'f"In case *any drip :should be formed 'by themeltingtofdust onfthe projecting portions ofthe blocks '226,

form a drip ledge, thefcurrentsv of air frm theipa'ssages 8Ov bylcreating a Acool air z onehextending to the inner edge of the blocksI`wouldfcooperatewith they inclined innersurfaces -of the blocks tovcausethe drip to solidify into a, slag or clinker projecting downwardlyand inwardly 'from the inner edge of the blocks in substantiallyV theplane of the inclinedl inner surfaces as indicated at 40 in Figure 3,.and it will be moneta side portions of the blocks and blocking thev airpassages. f

`VJhile the features described above are well adapted for use in thetype of furnace illustrated in the drawings, it isfto be understoodthat; except as. defined in -the claims, certain features ofthe'invention are y not limited to usein a furnace embodying any or `allofthe other features as they may be used in other types of furnaces.

What I claim is r.

l. A lire box fora pulverized fuel furnace of the class in which thecombustion of the fuel, takes place While it is in suspension, havingone of its side walls provided with a horizontal recess extendinglongitudinally thereof, a series of blocks set into said recess andspaced from theback wall thereof so as to form an air passagevbetweensaid wall of the recess and said blocks, the under side of saidblocksprojecting inwardly beyond the'adjacent portion of the vside wall,each,

of said blocks having a channel in its top surface lead-ing from saidair passage and spaced from the inner end of the block and an air ductleading from the channel downwardly through the bottom sideof the blockwith the backwall of the duct vsubstantially in the plane of the portionof the ire wall below the block.

2. A fire boX for a furnace having a side wall thereof provided lwith aplurality of downwardly and inwardlyinclined surfaces arranged one abovethe other, and a row of bricks defining the upperv edge lof eachof saidinclined surfaces, projecting a distance inwardly beyond said upper edgeand having'ducts-.of substantially the same inclination with theirbackwalls arranged substanan outlet in -a-n upper `part thereof, meansllO for admitting the fuel in an upper partl of the chamber in adownward direction so that the fuel and flaniestream reverts on itselfsubstantially U-form, means for admit-- an outlet in. an upper partthereof, means for admitting the fuel in an upper part of the chamber'in a downward direction so that the fuel and flame stream will reverton itself in a substantially 4U-form, and means for admitting a'downwardly directed body of air between the fuel and flame stream andthe four upright walls of the chamber.

5. A pulverized fuel furnace having, in combination, a combustionchamber having an outlet in an upper part thereof,` means for admittingthe fuel in an upper part of the chamber in a downward direction so thatthe fuel and flame stream reverts on itself in a substantially U-form,and means for admitting a downwardly directed body of air between thefuel and Haine stream and the four upright walls of the chamber at aplurality of points in the height of the chamber.

6. A pulverized fuel furnace having, in

combination, a combustion chamber having an outlet in an upper partthereof, means for admitting the fuel and a portion of the air requiredfor combustion in an upper part of the chamber in a downward direction,so that the fuel and flame stream reverts on itself ina substantiallyUfform, and means foradmittin further air for combustion at successivepoints in the height of the furnace and below the point of admission ofthe fuel,

such air being directed downwardly by said means.

7. A pulverized fuel furnace having, in combination, a combustionchamber, means for admitting the fuel adjacent the wall of the chamberand in a direction generally substantially paralleltherewith, and meansfor admitting a combustion supporting medium through such wall in astream directed thereby generally substantially parallel with theentering stream of fuel and at a point below the point of admission ofthe fuel.

8. A pulverized fuel furnace having, in combination, a combustionchamber, means for admitting the fuel adjacent the wall of the chamberand in a direction generally substantially parallel therewith, and meansfor 'admitting a combustion supporting medium through such wall in astream directedv thereby generally substantially parallel with theentering stream of fuel and moving in the same general direction and ata v point below the point of admission of the fuel.

9. A pulverized ruel furnace having, in combination, a combustionchamber having an outlet in an upper part thereof, means for admittingthe fuel at a point such that the fuel and flame stream in progress tirough the chamber rises toward said outf let, and' means for admitting adownwardly directed body of air between the rising portion of the liamestream and the adjacent chamber wall structure.

l0. A ulverized fuel furnace having, in combination, a combustionchamber having an outlet in an upper part thereof, means for admittingthe fuel at a point such that the fuel and flame stream in progressthrough the chamber rises toward the outlet, and means for admitting adownwardly directed body of air between the rising portion of the amestream and the adjacent chamber wall structure at a plurality of pointsin the height of the furnace.

1l. ln a furnace, a combustion chamber having a substantially verticalwall, means for introducing a stream of pulverized fuel mixed with airdownwardly into the combustion chamber at a distance from said wall, andmeans for causing air under pressure to be introduced into thecombustion chamber so that' it flows downwardly along said wall in atuin, laterally extended stream substantially the width of the wall andwider than the fuel stream.

12. In a furnace, a combustion chamber having a substantially verticalwall and a draft outlet, means for introducing a stream of pulverizedfuel mixed with air downwardly into the combustion chamber so that ittakes a return bent course to the draftoutlet, and means for introducingair to the combustion chamber between the fuel stream and wall providedwith an air orifice approximately the width of the wall and with meansfor directing the air downwardly along said wall.

13r A furnace for the combustion of line fuel, one wall of which isprovided with a tuyre for the admission of supplementary air, the tuyreopening discharging parallel to the inner face of the wall and in thedirection of flow of the products of combustion, and means for supplyinga flow of air under pressure through said tuyre and along said wall.

lll. ln a furnace, a combustion chamber having a substantially Verticalwall and a draft Opening, means for introducing a stream of pulverizedfuel mixed with air downwardly into the combustion chamber at a distancefrom said wall so that the fuel in combustion takes a return bent coursethrough the combustion chamber, and means for causing air under pressureto be introduced into the combustion chamber so that it: flowsdownwardly along said wall in a stream substantially wider than the fuelstream.

GEORGE PERCY JACKSON.

